-eliminating duplicate code

1 files changed, 73 insertions, 84 deletions

diff --git a/src/fs/fs_download.c b/src/fs/fs_download.c
index 490beef5e..d91c9e824 100644
--- a/src/fs/fs_download.c
+++ b/src/fs/fs_download.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001-2011 Christian Grothoff (and other contributing authors)
+     (C) 2001-2012 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -21,9 +21,6 @@
  * @file fs/fs_download.c
  * @brief download methods
  * @author Christian Grothoff
- *
- * TODO:
- * - different priority for scheduling probe downloads?
  */
 #include "platform.h"
 #include "gnunet_constants.h"
@@ -2003,16 +2000,7 @@ GNUNET_FS_download_signal_suspend_ (void *cls)
 
 
 /**
- * Download parts of a file.  Note that this will store
- * the blocks at the respective offset in the given file.  Also, the
- * download is still using the blocking of the underlying FS
- * encoding.  As a result, the download may *write* outside of the
- * given boundaries (if offset and length do not match the 32k FS
- * block boundaries). <p>
- *
- * This function should be used to focus a download towards a
- * particular portion of the file (optimization), not to strictly
- * limit the download to exactly those bytes.
+ * Helper function to setup the download context.
  *
  * @param h handle to the file sharing subsystem
  * @param uri the URI of the file (determines what to download); CHK or LOC URI
@@ -2028,38 +2016,27 @@ GNUNET_FS_download_signal_suspend_ (void *cls)
  * @param anonymity anonymity level to use for the download
  * @param options various options
  * @param cctx initial value for the client context for this download
- * @param parent parent download to associate this download with (use NULL
- *        for top-level downloads; useful for manually-triggered recursive downloads)
  * @return context that can be used to control this download
  */
 struct GNUNET_FS_DownloadContext *
-GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
-                          const struct GNUNET_FS_Uri *uri,
-                          const struct GNUNET_CONTAINER_MetaData *meta,
-                          const char *filename, const char *tempname,
-                          uint64_t offset, uint64_t length, uint32_t anonymity,
-                          enum GNUNET_FS_DownloadOptions options, void *cctx,
-                          struct GNUNET_FS_DownloadContext *parent)
+create_download_context (struct GNUNET_FS_Handle *h,
+                         const struct GNUNET_FS_Uri *uri,
+                         const struct GNUNET_CONTAINER_MetaData *meta,
+                         const char *filename, const char *tempname,
+                         uint64_t offset, uint64_t length, uint32_t anonymity,
+                         enum GNUNET_FS_DownloadOptions options, void *cctx)
 {
   struct GNUNET_FS_DownloadContext *dc;
 
   GNUNET_assert (GNUNET_FS_uri_test_chk (uri) || GNUNET_FS_uri_test_loc (uri));
-
   if ((offset + length < offset) ||
       (offset + length > GNUNET_FS_uri_chk_get_file_size (uri)))
   {
     GNUNET_break (0);
     return NULL;
   }
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting download `%s' of %llu bytes\n",
-              filename, (unsigned long long) length);
   dc = GNUNET_malloc (sizeof (struct GNUNET_FS_DownloadContext));
   dc->h = h;
-  dc->parent = parent;
-  if (parent != NULL)
-  {
-    GNUNET_CONTAINER_DLL_insert (parent->child_head, parent->child_tail, dc);
-  }
   dc->uri = GNUNET_FS_uri_dup (uri);
   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
   dc->client_info = cctx;
@@ -2081,22 +2058,74 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
       GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
   dc->treedepth =
       GNUNET_FS_compute_depth (GNUNET_FS_uri_chk_get_file_size (dc->uri));
-  if ((filename == NULL) && (is_recursive_download (dc)))
+  if ((NULL == filename) && (is_recursive_download (dc)))
   {
-    if (tempname != NULL)
+    if (NULL != tempname)
       dc->temp_filename = GNUNET_strdup (tempname);
     else
       dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
   }
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Download tree has depth %u\n",
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
+              "Starting download `%s' of %llu bytes with tree depth %u\n",
+              filename,
+              (unsigned long long) length,
               dc->treedepth);
-  if (parent == NULL)
-  {
+  dc->task = GNUNET_SCHEDULER_add_now (&GNUNET_FS_download_start_task_, dc);
+  return dc;
+}
+
+
+/**
+ * Download parts of a file.  Note that this will store
+ * the blocks at the respective offset in the given file.  Also, the
+ * download is still using the blocking of the underlying FS
+ * encoding.  As a result, the download may *write* outside of the
+ * given boundaries (if offset and length do not match the 32k FS
+ * block boundaries). <p>
+ *
+ * This function should be used to focus a download towards a
+ * particular portion of the file (optimization), not to strictly
+ * limit the download to exactly those bytes.
+ *
+ * @param h handle to the file sharing subsystem
+ * @param uri the URI of the file (determines what to download); CHK or LOC URI
+ * @param meta known metadata for the file (can be NULL)
+ * @param filename where to store the file, maybe NULL (then no file is
+ *        created on disk and data must be grabbed from the callbacks)
+ * @param tempname where to store temporary file data, not used if filename is non-NULL;
+ *        can be NULL (in which case we will pick a name if needed); the temporary file
+ *        may already exist, in which case we will try to use the data that is there and
+ *        if it is not what is desired, will overwrite it
+ * @param offset at what offset should we start the download (typically 0)
+ * @param length how many bytes should be downloaded starting at offset
+ * @param anonymity anonymity level to use for the download
+ * @param options various options
+ * @param cctx initial value for the client context for this download
+ * @param parent parent download to associate this download with (use NULL
+ *        for top-level downloads; useful for manually-triggered recursive downloads)
+ * @return context that can be used to control this download
+ */
+struct GNUNET_FS_DownloadContext *
+GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
+                          const struct GNUNET_FS_Uri *uri,
+                          const struct GNUNET_CONTAINER_MetaData *meta,
+                          const char *filename, const char *tempname,
+                          uint64_t offset, uint64_t length, uint32_t anonymity,
+                          enum GNUNET_FS_DownloadOptions options, void *cctx,
+                          struct GNUNET_FS_DownloadContext *parent)
+{
+  struct GNUNET_FS_DownloadContext *dc;
+
+  dc = create_download_context (h, uri, meta, filename, tempname,
+                                offset, length, anonymity, options, cctx);
+  if (NULL == dc)
+    return NULL;
+  dc->parent = parent;
+  if (NULL != parent)
+    GNUNET_CONTAINER_DLL_insert (parent->child_head, parent->child_tail, dc);
+  else
     dc->top =
         GNUNET_FS_make_top (dc->h, &GNUNET_FS_download_signal_suspend_, dc);
-  }
-  dc->task = GNUNET_SCHEDULER_add_now (&GNUNET_FS_download_start_task_, dc);
   return dc;
 }
 
@@ -2146,62 +2175,22 @@ GNUNET_FS_download_start_from_search (struct GNUNET_FS_Handle *h,
 {
   struct GNUNET_FS_DownloadContext *dc;
 
-  if ((sr == NULL) || (sr->download != NULL))
+  if ((NULL == sr) || (NULL != sr->download))
   {
     GNUNET_break (0);
     return NULL;
   }
-  GNUNET_assert (GNUNET_FS_uri_test_chk (sr->uri) ||
-                 GNUNET_FS_uri_test_loc (sr->uri));
-  if ((offset + length < offset) ||
-      (offset + length > sr->uri->data.chk.file_length))
-  {
-    GNUNET_break (0);
+  dc = create_download_context (h, sr->uri, sr->meta, filename, tempname,
+                                offset, length, anonymity, options, cctx);
+  if (NULL == dc)
     return NULL;
-  }
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting download `%s' of %llu bytes\n",
-              filename, (unsigned long long) length);
-  dc = GNUNET_malloc (sizeof (struct GNUNET_FS_DownloadContext));
-  dc->h = h;
   dc->search = sr;
   sr->download = dc;
-  if (sr->probe_ctx != NULL)
+  if (NULL != sr->probe_ctx)
   {
     GNUNET_FS_download_stop (sr->probe_ctx, GNUNET_YES);
     sr->probe_ctx = NULL;
   }
-  dc->uri = GNUNET_FS_uri_dup (sr->uri);
-  dc->meta = GNUNET_CONTAINER_meta_data_duplicate (sr->meta);
-  dc->client_info = cctx;
-  dc->start_time = GNUNET_TIME_absolute_get ();
-  if (NULL != filename)
-  {
-    dc->filename = GNUNET_strdup (filename);
-    if (GNUNET_YES == GNUNET_DISK_file_test (filename))
-      GNUNET_break (GNUNET_OK == GNUNET_DISK_file_size (filename, &dc->old_file_size, GNUNET_YES, GNUNET_YES));
-  }
-  if (GNUNET_FS_uri_test_loc (dc->uri))
-    GNUNET_assert (GNUNET_OK ==
-                   GNUNET_FS_uri_loc_get_peer_identity (dc->uri, &dc->target));
-  dc->offset = offset;
-  dc->length = length;
-  dc->anonymity = anonymity;
-  dc->options = options;
-  dc->active =
-      GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
-  dc->treedepth =
-      GNUNET_FS_compute_depth (GNUNET_ntohll (dc->uri->data.chk.file_length));
-  if ((filename == NULL) && (is_recursive_download (dc)))
-  {
-    if (tempname != NULL)
-      dc->temp_filename = GNUNET_strdup (tempname);
-    else
-      dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
-  }
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Download tree has depth %u\n",
-              dc->treedepth);
-  dc->task = GNUNET_SCHEDULER_add_now (&GNUNET_FS_download_start_task_, dc);
   return dc;
 }